Research On Critical Of ATSE Issue Conversion

In order to ensure continuous power supply of important load,Automatic Transfer Switching Equipment (ATSE) has been widely used. But switching inrush current and over voltage will occur in the process of power conversion, which is harmful to the load and power, it even can lead to the failure of standby power switch. So Studying transient characteristics of different loads in power supply conversion can avoid the greater impact in switch on and ensure fast and smooth power supply during the conversion process. On the basis of the status and trend of ATSE, the paper researches the features and applications of CB-level and PC-level in depth. The results show that the PC-class products with intelligent controller and fast conversion have a broader develop space.Because of the presence of residual voltage, The induction motor loads may produce more than 10 times rated current of switching inrush current and higher operating voltage in standby power switch. Moreover, capacitive load in the transition process has relationship with phase angle of standby power, the worst switch on angle may produce 4 times switch current and almost 2 times over-voltage.The paper uses Matlab simulation methods and establishes the power conversion model of induction motor type load and capacitive load in different conditions. By statistics the standby power switch at different initial phase over-current and over-voltage situations of the main power random outage, the paper gets the transient features of induction motor in different case. By analysis the minimum time of transient closing value, the minimum inrush current will emerge when the phase of the standby power loss is similar to the motor residual voltage's, maximum inrush current will occurs when the above phase is opposite, which can avoid the adverse closing moments. Simulated results of over-voltage and over-current when capacitive load switching show that when the load power factor is smaller, the inrush current and over-voltage will be bigger in switch on, and the maximum inrush current and over-voltage will occur when the power supply instantaneous voltage is biggest, instantaneous wave is smallest when the power supply instantaneous voltage is minimum. The standby power is input when the three-phase voltage with zero value, which can make the over-voltage and switching inrush current value in capacitive load. By finding the minimum phase angle when standby power generates over-voltage and over-current and use closing phase independence will produce smaller over-current and over-voltage value than the most adverse situations.